GFB

I don't have a TDR account. What did he find out caused the miss?

NoSeeUm

I just ordered a ZXT+. I want to stack it with my TST.

Currently the maximum TST MAP pass through equates to about 5 psi of boost. The TST also does defueling using boost fooling for high EGT. I am not sure if high or low boost fooling is used though (maybe I should test to find out ). Shouldn't be a big issue because I seldom bang on EGT's anyways.

What would the maximum ZXT+ pass through be?
I am thinking that maybe the ZXT+ messes with the boost signal to make the ECM fuel harder?

I have been tossing around adding a second MAP sensor just for the ZXT+. This would let each box gets its own signal and to let the ZXT+ convince the ECM to fuel using boost fooling (if it does so). With two MAP's it might be better to stack the ECM connector on top of the ZXT+. With a single MAP stack, the TST will just clip any ZXT+ boost fooling to a maximum of 5 psi.

Any pro's or con's either way? Other than the expense.

If I go with one MAP sensor, hopefully someone knows if I should stack the ZXT MAP connector first or second? I looked, but could not relocate where I had read this before.

TIA;
Jim

bama

to much timing.there are a couple of guys working on this.some trucks do it,some dont.claims that edge even admitted to knowing it,but its a small fraction of overall trucks,so they dont worry with addressing it...anyhow,he ended up running a 1kohm resistor in place of iat sensor,so as the computer would think its hot and retard timing.these guys are having the same issues i have been having,so it was a good read for me.......this afternoon,i tried running the 1k resistor on mine.no bucking,but also not quite the performance or smoke i get regularly.this was with the hrvp tune also,so it might feel pretty good with the aggressive tune.the problem with doing this is in the cold starts,the computer needs to know the iat temp to help determine what timing to run......maybe quad could make a program with a good bit less timing?i dont know,maybe i should try a fueling only box?.........bama

NoSeeUm

I have been thinking about this IAT bomb for some time. I have thought about relocating my IAT out of the manifold. This partly because I run an exhaust brake and partly to control timing advance. Which for some reason I find annoying.

My idea would be to provide a switchable circuit so that I could swap the ECM input to a steady resistance value using a resistor (rheostat) or to the IAT. Switchable so that the grid heaters would still work correctly.

My plan is to let the ZXT+ do the timing for me if I feel I need it with the resistor switched in, but other wise be able to run with minimal extra timing so that my truck runs quieter. Then again I could always add the ZXT+ timing when I am plodding out some miles on the highway for better economy. I would set the resistance to what I feel the truck runs the quietest, which I think is around 80-100F IAT. EGT's are not an issue for me.

Anyone have any pro's or con's?

Jim

NoSeeUm

I am pretty sure no one has requested it, but is the ZXT+ also capable of retarding the timing?

TIA, sorry to be a pain:
Jim

bama

these guys are running a 1k in parallel with the sensor,with the resistor ran through a switch in the cab.so then you could cut it off(open)and read off iat for cold starts and grid heaters,then once up to operating temp,close switch to hold the temp readings needed for timing.using a pot would be ideal for fine tuning though........my iat was reading 7.6,7.7 at 85 degrees...i believe at 85 degrees it should be at 6.6 or 6.7..........gotta love electronics,you know?.......bama

NoSeeUm

7.6 as in volts I am assuming?

Jim

bama

no,,ohms......7.6k ohms.......you can look on fritzs ram home page for the values of the sensor.......the thinking is,the higher the resistance,the colder it thinks it is,and the more timing it adds...the lower the resistance,the hotter it thinks it is,and retards timing.....the thinking is that some trucks,for some reason or another,come from the factory with more base timing than others.then when a timing box is added,it over advances the timing and you get the bucking......on mine,when i had the iat out and used the 1k ohm resistor,which i would think had the truck with virtually no timing,it didnt buck or anything,and when you would flip the switch for the box on,the motor would immediately pick up some,without even touching the pedal.......................i bet quad wishes i would go away by now,he-he..............bama

GFB

Hmmmmmmmmmm. I can't run out to the truck to look at the MAP plug right now, but I'm assuming it's just two wires??? Seems like a couple wire taps, switch, radio shack resistor, and two lengths of wire might make be needed for a quick project after work.

qzilla

How about I just turn the timing back some and see if it makes and improvement?

bama

quad,,that would be great..........gfb,its two wires,and im talking about the iat sensor,not the map..........bama

jshaw214

I have a 2000 and just bought the XZT+ and stacked it with my Big Hoss
(thanks GFB!) I downloaded the aggressive tune and went to the drag strip. Wow, I love that feeling of flipping the switch and you get put in your seat a little bit further.
I did notice that I had bad bucking issues just cruising at any speed but like everyone else getting on it or off it I had no problem. I also was curious since I saw nothing in my instructions about the toggle switch settings locations.
Is center OFF? There is a little nub on a washer or something under the toggle where all the mounting nuts and washers are and when I flip it that way is when I can feel it kick in. When I flip the toggle to opposite side I really did not feel anything so I thought there was only one setting but I guess I am wrong. So which direction is timing? and off and timing and fuel?
I love the ease of the box and can't wait for some meaner tunes. I have surging issues that are caused by my Banks and loping issues caused by my Jammer 3's. Also, I thought you only got the 70hp if you had a commander plugged in?
Thanks Quad

NoSeeUm

Thanks, funny my spreadsheet curve told my that 8k was about the size I needed to just put one in paralell and leave it there.

QZilla, side tracked your thread, my aploogies. Mind backing up a few posts and taking a look at my stacking the MAP sensor connection questions?

Jim

hamilton71801

I have the same question as you. I can turn on what I think is timing only and feel no difference between off and timing. I was even pulling my TT this weekend and noticed no difference in EGT's, FP being pulled down or my mileage computer changing between off and timing. With my Superchips, you could notice the difference on the gauges even on the lowest setting and I think it was a timing only programmer. I'm still happy with the XZT+ but the jury's still out on the mileage increase...I'm still waiting on a road trip to see how she does.

skidooer76

I have a 2001 Dodge and put the XZT+ on and had no milage gains on the timming only setting but when I put it on the performance setting I gain around 5 MPGS, I thought the timming setting was supposed to give you better fuel economy than the stock and performance setting?????
The truck has RV 325 inj,5"straight pipe,K&N intake. I am also experiencing some mild bucking when I am at constant speeds and when the cruise is set, I am still running the performance tune that came on the box from the factory.

Any help would be great.